高压隔离开关静触头铸铝夹板的断裂失效分析

Fracture Failure Analysis on Cast Aluminum Alloy Splint of High Voltage Isolation Switch Static Contact

隔离开关静触头ZL101A铸铝夹板在使用过程中发生了多起断裂。利用光谱仪、光学显微镜、扫描电子显微镜进行成分、组织特征以及断口分析。结果表明,ZL101A铸铝夹板的共晶Si呈粗大颗粒状,集中分布在晶界,并出现过热现象。螺栓、垫片与铸件壁发生干涉,在夹板的螺栓孔附近形成较大的应力。在此应力的作用下,裂纹沿着晶界扩展,发生脆性断裂。

ZL101A cast aluminum alloy splints of high voltage isolation switch static contact in the use of the process had many cases of fracture failure. Spectrometer, optical microscopy and scanning electron microscopy were used for component identification test,microstructure feature and fracture morphology analysis. The results show that eutectic Si of ZL101 A cast aluminum alloy splints are coarse spherical and gather in the grain boundaries,and an overheating phenomenon is observed. Bolts and gaskets had an interference with the casting wall so that the great stresses were formed around bolt holes of these splints. Under the action of stresses,crack propagated along grain boundaries,and these splints eventually occurred brittle fracture.